x86/boot/efi: Fix __KERNEL_CS definition of GDT entry on 64-bit configurations

Define __KERNEL_CS GDT entry as long mode (.L=1, .D=0) on 64-bit
configurations.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170606113133.22974-5-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 1d5093d1f319bb71a9310ada7b548d87fe791a51..b75c20f779ead87df0098e2580e4bc460d8818ef 100644 (file)
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1059,8 +1059,13 @@ struct boot_params *efi_main(struct efi_config *c,
        desc->p = 1;
        desc->limit = 0xf;
        desc->avl = 0;
-       desc->l = 0;
-       desc->d = SEG_OP_SIZE_32BIT;
+       if (IS_ENABLED(CONFIG_X86_64)) {
+               desc->l = 1;
+               desc->d = 0;
+       } else {
+               desc->l = 0;
+               desc->d = SEG_OP_SIZE_32BIT;
+       }
        desc->g = SEG_GRANULARITY_4KB;
        desc->base2 = 0x00;
        desc++;